Provide ability to decompress response using any header, not just Content-Encoding

[asarkar]

Expected behavior

Decompress server response in GZIP format. Currently, HttpClientOptions has an acceptGzip option, which adds a HttpContentDecompressor. Problem is, HttpContentDecompressor works only based on Content-Encoding header, and not all servers are well-behaved citizens of HTTP. The server I'm dealing with doesn't return a Content-Encoding header, but sets the Content-Type = application/x-gzip,and there's nothing I can do to change that.

Also created netty/netty#7553 since change will be required in Netty too to support this.

Actual behavior

Response is not decompressed.

Steps to reproduce

Create a rogue server that returns compressed response without Content-Encoding header.

Reactor Netty version

0.7.2.RELEASE

JVM version (e.g. java -version)

Irrelevant.

OS version (e.g. uname -a)

Irrelevant.